Pivoted lever brake structure

Abstract

A braking gear having two turnable levers coupled by a spring and carrying brake shoes which engage the disk of the machine to be braked at both sides thereof and a double-acting hydraulic cylinder mechanically connected with the turnable levers by way of an articulation double-link members. The double-link member has a common articulation joint which is connected with the piston rod of the hydraulic cylinder. The ends of the articulation double-link member are connected with the levers and are acted upon by the spring, coupling the turnable levers, due to which the levers are reliably fixed both when the braking gear is switched on or off.

What is claimed is: 
     
       1. A braking gear comprising, two symmetrical arcuate brake levers pivoted at one end about a common pivot point and symmetrically disposed about an axis of symmetry passing through said common pivot point, two brake shoes each mounted on a free end of a respective one of said arcuate brke levers, each said free end being spaced from said common pivot point, a toggle system having two levers each pivotally connected to a corresponding arcuate brake lever and pivotally connected at a pivot at one end on said axis of symmetry, and having a third lever disposed along said axis of symmetry connected at the last-mentioned pivot and disposed extending axially between the arcuate brake levers, means to actuate said third lever axially to move said pivot of said two levers along the axis of symmetry to move the free ends of the arcuate levers toward each other or away from each other to thereby move the brake shoes toward said axis of symmetry for braking a moving element disposed between the brake shoes or away from said axis of symmetry, and fluid-actuated, double-acting means to additionally vary the distance between pivot points at which said two levers are connected to said arcuate levers thereby to additionally variably control the movement of said brake shoes toward and away from said axis. 
     
     
       2. A braking gear according to claim 1, in which said means to actuate said third lever comprises a cylinder pivotally connected to said common pivot point, and means in said cylinder for actuating said third lever axially. 
     
     
       3. A braking gear according to claim 1, in which said means to additionally vary the distance between said pivot points comprises a second system of toggle levers connected to said common pivot and said pivot on said axis of symmetry. 
     
     
       4. A braking gear comprising, two symmetrical arcuate brake levers pivoted at one end about a common pivot point and symmetrically disposed about an axis of symmetry passing through said common pivot point, two brake shoes each mounted on a free end of a respective one of said arcuate brake levers, each said free end being spaced from said common pivot point, a toggle system having two levers each pivotally connected to a corresponding arcuate brake lever and pivotally connected at a pivot at one end on said axis of symmetry, and having a third lever disposed along said axis of symmetry connected at the last-mentioned pivot and disposed extending axially between the arcuate brake levers, means to actuate said third lever axially to move said pivot of said two levers along the axis of symmetry to move the free ends of the arcuate levers toward each other or away from each other to thereby move the brake shoes toward said axis of symmetry for braking a moving element disposed between the brake shoes or away from said axis of symmetry, and means to additionally vary the distance between said arcuate levers comprising a cylinder pivotally connected to one of said arcuate levers and having a piston reciprocable therein having a piston rod connect to the other of said arcuate levers variably varying said distance between the arcuate levers with said means to actuate said third lever.